Receive call on mobile; then, minute later dead air.
Click on RC icon, swipe down from very top of screen and message ''switch to this device'' appears. Must click approval to reconnect caller.
If call is initiated from mobile, this situation never happens. Incoming only.
iPhone 8 , iOS 12.1.4
I may have solved the case. I deleted the app from my phone, rebooted and re-installed earlier today. Have received a couple of calls without incidence (oh! those nasty little ones and zeroes when they decide not to play nice). Thanks for the reply Jessica.